一个简单计算器代码(python)

import tkinter as tk
from tkinter import messagebox
class Calculator:
    def __init__(self, master):
        self.master = master
        master.title("简单计算器")
        # 创建输入框
        self.entry = tk.Entry(master, width=20, font=("Arial", 16))
        self.entry.grid(row=0, column=0, columnspan=4, padx=10, pady=10)
        # 创建按钮
        self.create_button("7", 1, 0)
        self.create_button("8", 1, 1)
        self.create_button("9", 1, 2)
        self.create_button("+", 1, 3)
        self.create_button("4", 2, 0)
        self.create_button("5", 2, 1)
        self.create_button("6", 2, 2)
        self.create_button("-", 2, 3)
        self.create_button("1", 3, 0)
        self.create_button("2", 3, 1)
        self.create_button("3", 3, 2)
        self.create_button("*", 3, 3)
        self.create_button("0", 4, 0)
        self.create_button(".", 4, 1)
        self.create_button("=", 4, 2)
        self.create_button("/", 4, 3)

        # 创建清空按钮
        self.create_button("C", 5, 0, columnspan=2)
        self.create_button("DEL", 5, 2, columnspan=2)
    def create_button(self, text, row, column, columnspan=1):
        button = tk.Button(self.master, text=text, width=5, height=2, font=("Arial", 16), command=lambda: self.on_button_click(text))
        button.grid(row=row, column=column, columnspan=columnspan, padx=5, pady=5)
    def on_button_click(self, text):
        if text == "=":
            try:
                result = eval(self.entry.get())
                self.entry.delete(0, tk.END)
                self.entry.insert(tk.END, str(result))
            except:
                messagebox.showerror("错误", "输入有误")
        elif text == "C":
            self.entry.delete(0, tk.END)
        elif text == "DEL":
            self.entry.delete(len(self.entry.get())-1, tk.END)
        else:
            self.entry.insert(tk.END, text)
root = tk.Tk()
calculator = Calculator(root)
root.mainloop()